1. Field of the Invention
This invention relates to lens forming equipment and, more particularly, to an improved, automatic lens edge grinder. The invention is specifically directed to an attachment for lens blank edging equipment. A frame follower senses the inside contour of a spectacle frame and transmits its sensings to beveling equipment to thereby eliminate the need for patterns or templates for each lens configuration.
2. Description of the Prior Art
Typical prior art edging machines employ patterns or templates in the shape of the inside contour of an eyeglass frame socket for controlling the duplication of the lens edge in an ophthalmic lens edging machine. Each different lens configuration required a different pattern. The patterns for each and every lens size or style had to be catalogued and stored for later use.
Some prior art devices have been developed which have mechanisms to follow the inside contour of a frame for the purpose of duplicating this contour on the edge of the lens to be ground. One such device is disclosed in U.S. Pat. No. 3,572,855 to Charles R. Bright. The Bright device includes a plurality of U-shaped, air and vacuum-biased cam means which detect the contour of the frame. Such an approach can introduce errors into the lens grinding operation due to the finite number of measurements which are taken about the periphery. Other interesting teachings include the United States patent to Clar U.S. Pat. No. 3,170,374, Feb. 23, 1965, and to Novak, U.S. Pat. No. 3,555,739, Jan. 19, 1971. Each of these teachings utilizes the interior of a frame socket to form a corresponding periphery.